Since the 13th century Lateran IV teaching on creation was assimilated into the Vatican I Council, it is sufficient to examine the wording of the 1215 dogma to understand the significance of the term simul for the Vatican I fathers:

In the following DenzingerEnglish translation, the underlined word simul in Latin is translated as “at once” connoting direct creation (from nothing):

God…creator of all visible and invisible things, of the spiritual and of the corporal; who by His own omnipotent power at once from the beginning of time created each creature from nothing, spiritual and corporal, namely, angelic and mundane, and finally the human, constituted as it were, alike of the spirit and the body (D.428).

A reference in the French text of the CCC (327) should be taken as definitive since it translates simul as “tout ensemble,” i.e. all things were created together. It reads:

Yet despite the identical meaning of these translations a second diametrically opposed meaning was introduced in the latter part of the nineteenth century allowing for things to be created at intervals over millions of years. As the Council’s dogma says that “all things” were created “at oncefrom the beginning of time,” the conflict between the two meanings is more than transparent.